About Gtk+

GTK (Gimp Toolkit) is a library for creating graphical user interfaces. It is licensed using the LGPL license, so you can develop open software, free software, or even commercial non-free software using GTK without having to spend anything for licenses or royalties.

It's called the GIMP toolkit because it was originally written for developing the GNU Image Manipulation Program (GIMP), but GTK has now been used in a large number of software projects, including the GNU Network Object Model Environment (GNOME) project. GTK is built on top of GDK (GIMP Drawing Kit) which is basically a wrapper around the low-level functions for accessing the underlying windowing functions (Xlib in the case of the X windows system), and gdk-pixbuf, a library for client-side image manipulation.

The primary GTK authors are:

• Petre Mattis <petm@xcf.berkeley.edu>

• Spencer Kimball <spencer@xcf.berkeley.edu>

• Josh Macdonald <jmacd@xcf.berkeley.edu>

GTK is currently maintained by:

• Owen Taylor <otaylor@redhat.com>

• Tim Janik <timj@gtk.org>

GTK is essentially an object oriented application programmers interface (API). Although written completely in C, it is implemented using the idea of classes and callback functions (pointers to functions).